1. Technical Field
The present invention relates to a flow path member having a liquid flow path provided therein, a liquid ejecting head, a liquid ejecting apparatus, and a liquid stirring method of stirring liquid and, particularly, relates to a flow path member using ink as the liquid, an ink jet type recording head, an ink jet type recording apparatus, and an ink stirring method.
2. Related Art
A liquid ejecting apparatus represented by an ink jet type recording apparatus, such as an ink jet type printer and a plotter, includes a liquid ejecting head which can eject droplets of liquid, such as ink stored in a cartridge and a tank.
In an ink jet type recording head as a representative example of a liquid ejecting head ejecting liquid droplets, For example, a pressure generation chamber which communicates with nozzle openings through which ink is ejected and a pressure generation unit which causes a pressure change of the ink in the pressure generation chamber are provided and ink droplets are ejected from the nozzle openings by causing the pressure generation unit to cause a pressure change of the ink in the pressure generation chamber.
In a case of such an ink jet type recording head, in ink not subjected to distribution over the respective pressure generation chambers, a laminar flow having a high concentration and a laminar flow having a low concentration are formed in liquid due to sedimentation of components contained in the ink. When the ink having the laminar flow described above is supplied, without change, to the respective pressure generation chamber, the nozzle openings are divided into a group of nozzle openings through which the ink having a high concentration is ejected and a group of nozzle openings through which the ink having a low concentration is ejected. As a result, there is a problem in that unevenness of concentration occurs in a printing result.
Accordingly, an ink jet printer in which a sub-tank is provided in a flow path not subjected to distribution over respective pressure generation chambers and ink is stirred by a stirring sphere provided in the sub-tank is proposed (see JP-A-2010-184424, for example).
In addition, a liquid discharging head in which a flow path branches in the middle of a flow path and ink in each branched flow path is heated by a heater, in such a manner that the ink is effectively heated is proposed (see JP-A-2010-76176, for example).
However, in a configuration in which the ink is stirred by the stirring sphere, as in the case of JP-A-2010-184424, when the sub-tank is stopped, the stirring sphere does not move. As a result, there is a problem in that an ink stirring effect cannot be obtained. Furthermore, when a stirring unit, such as a stirring sphere, is provided, there is a problem in that the size of the ink jet type recording head is increased.
An ink jet type recording apparatus in which ink is stirred by causing the ink to be circulated in a portion between a storage unit storing the ink and an ink jet type recording head is proposed. However, there is a problem in that the size of the ink jet type recording apparatus is increased because it is necessary to provide a circulation unit.
Even when the flow path branches, as in the case of JP-A-2010-76176, there is a problem in that the ink cannot be effectively stirred.
The problems described above are not limited to a liquid ejecting head represented by an ink jet type recording head and a liquid ejecting apparatus but is shared by a flow path member used in other devices.